WO2015046830A1

WO2015046830A1 - Method for transceiving downlink data channel and apparatus therefor

Info

Publication number: WO2015046830A1
Application number: PCT/KR2014/008763
Authority: WO
Inventors: 박규진; 최우진
Original assignee: 주식회사 케이티
Priority date: 2013-09-30
Filing date: 2014-09-22
Publication date: 2015-04-02

Abstract

The present invention relates to a method for transceiving a downlink data channel and an apparatus therefor, the method according to an embodiment of the present invention for a base station to transmit PDCCH or EPDCCH comprising PDSCH scheduling information for a terminal, and PDSCH corresponding to the PDCCH or EPDCCH comprising the steps of: repetitively transmitting the PDCCH or EPDCCH by means of N number of downlink subframes; and repetitively transmitting the PDSCH by means of P number of downlink subframes, wherein, if the subframe index at which the repetitive transmission of PDCCH or EPDCCH ends is M, then the downlink subframe index at which the repetitive PDSCH transmission starts is M+k.

Description

Method and apparatus for transmitting / receiving downlink data channel

The present invention relates to a method and apparatus for transmitting and receiving a downlink data channel, and more particularly, to a method and apparatus for transmitting a downlink data channel for a machine type communication (MTC) terminal.

Machine Type Communication (MTC) or Machine to Machine (M2M) is communication between devices and things with no or minimal human intervention. "machine" may refer to an entity that does not require direct human intervention or intervention, and "MTC" may refer to a form of data communication that includes one or more such "machines." An example of a "machine" may be a smart meter or vending machine equipped with a mobile communication module, and recently, a smartphone that automatically connects to a network and performs communication without user intervention or intervention depending on the location or situation of the user. With the advent of the portable terminal having the MTC function is also considered as a form of "machine".

The MTC terminal may be installed in a place where the radio environment is worse than that of the general terminal. Therefore, the coverage of the MTC terminal should be improved to 20dB or more compared to the coverage of the general terminal.

In order for an MTC terminal to operate in coverage improved by 20 dB or more compared with a general terminal, it is necessary to repeatedly transmit control information and / or data of each physical channel transmitted only in one subframe unit in a plurality of subframes. In addition, when another LTE / LTE-Advanced terminal and the MTC terminal overlap the common search space, an error may occur when the MTC terminal checks the control information. Therefore, there is a need for a method of transmitting control information and data of a physical channel to suit the characteristics of the MTC terminal.

An object of the present invention is to provide a method and apparatus for transmitting and receiving a downlink data channel for an MTC terminal to overcome the above problems.

In order to solve the above-described problem, a method for transmitting a PDCCH or EPDCCH including PDSCH scheduling information for a UE by the base station according to an embodiment of the present invention and the PDSCH according thereto may include N downlink subframes of the PDCCH or the EPDCCH. Repeatedly transmitting through the PSCH, and repeatedly transmitting the PDSCH through P downlink subframes, and if the downlink subframe index at which repetitive transmission of the PDCCH or the EPDCCH is terminated is M, the PDSCH The downlink subframe index at which repetitive transmission is started is M + k.

According to another embodiment of the present invention, a method for receiving a PDCCH or EPDCCH including PDSCH scheduling information from a base station and the PDSCH according to the present invention includes repeatedly receiving the PDCCH or the EPDCCH through N downlink subframes, and And repeatedly receiving the PDSCH through P downlink subframes, and if the downlink subframe index at which repeated reception of the PDCCH or the EPDCCH is terminated is M, the downlink subframe at which the PDSCH repeat reception is started The frame index is M + k.

According to another embodiment of the present invention, a PDCCH or EPDCCH including PDSCH scheduling information for a UE and a base station transmitting the PDSCH according thereto may repeatedly transmit the PDCCH or the EPDCCH through N downlink subframes and transmit the PDSCH. When the transmitter repeatedly transmits through P downlink subframes and the downlink subframe index at which repeating transmission of the PDCCH or the EPDCCH is M, the downlink subframe index at which the PDSCH repeat transmission is started is M +. and a control unit for controlling the transmission unit to be k.

A terminal receiving a PDCCH or EPDCCH including PDSCH scheduling information and the PDSCH according thereto according to another embodiment of the present invention repeatedly receives the PDCCH or the EPDCCH through N downlink subframes, and receives the PDSCH. When the receiving unit repeatedly receives through P downlink subframes and the downlink subframe index at which repeated reception of the PDCCH or the EPDCCH is terminated is M, the downlink subframe index at which the PDSCH repeat reception is started is M +. and a control unit for controlling the receiving unit to be k.

When implementing the present invention can be implemented a method and apparatus for transmitting and receiving downlink data channel for the MTC terminal.

1 shows an example of a wireless communication system to which an embodiment of the present invention is applied.

2 illustrates an example of blind decoding PDCCH / EPDCCH and obtaining PDSCH scheduling information.

3 illustrates four PDCCH formats.

4 is a diagram showing the number of EREGs by ECCE.

5 is a diagram for a supported EPDCCH format.

6 is a diagram for transmitting a PDSCH after repeated transmission of a PDCCH / EPDCCH according to an embodiment of the present invention.

7 illustrates an example in which the number of PRBs, the number of repetitions, and the MCS are set according to a PDSCH format according to an embodiment of the present invention.

8 is a diagram illustrating repetitive transmission of a PDCCH or EPDCCH including PDSCH scheduling information according to an embodiment of the present invention, and transmission of the PDSCH accordingly.

9 is a diagram illustrating a process in which a base station repeatedly transmits a PDCCH or an EPDCCH to a UE according to an embodiment of the present invention.

10 is a diagram illustrating a process of repeatedly receiving a PDCCH or EPDCCH from a base station by a terminal according to an embodiment of the present invention.

11 is a diagram illustrating a configuration of a base station according to another embodiment.

12 is a diagram illustrating a configuration of a user terminal according to another embodiment.

Hereinafter, some embodiments of the present invention will be described in detail through exemplary drawings. In adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are assigned to the same components as much as possible even though they are shown in different drawings. In addition, in describing the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

In the present specification, the MTC terminal may mean a terminal supporting low cost (or low complexity) or a terminal supporting coverage enhancement. In the present specification, the MTC terminal may mean a terminal supporting low cost (or low complexity) and coverage enhancement. Alternatively, in the present specification, the MTC terminal may mean a terminal defined in a specific category for supporting low cost (or low complexity) and / or coverage enhancement.

In other words, in the present specification, the MTC terminal may mean a newly defined 3GPP Release-13 low cost (or low complexity) UE category / type for performing LTE-based MTC related operations. Alternatively, in the present specification, the MTC terminal supports enhanced coverage compared to the existing LTE coverage, or supports UE category / type defined in the existing 3GPP Release-12 or lower, or newly defined Release-13 low cost (or lower power consumption). low complexity) can mean UE category / type.

The wireless communication system in the present invention is widely deployed to provide various communication services such as voice, packet data, and the like. The wireless communication system includes a user equipment (UE) and a base station (base station, BS, or eNB). In the present specification, a user terminal is a comprehensive concept of a terminal in wireless communication. In addition, a user station (UE) in WCDMA and LTE / LTE-Advanced, HSPA, etc., as well as a mobile station (MS) and user interface (UT) in GSM It should be interpreted as a concept that includes a terminal, a subscriber station (SS), and a wireless device.

A base station 20 or a cell generally refers to a station that communicates with a user terminal, and includes a Node-B, an evolved Node-B, an Sector, and a Site. It may be called by other terms such as a base transceiver system (BTS), an access point, an access node, a relay node, a remote radio head (RRH), a radio unit (RU), and a small cell.

That is, in the present specification, the base station 20 or the cell is a partial area covered by a base station controller (BSC) in CDMA, a Node-B in WCDMA, an eNB or a sector (site) in LTE / LTE-Advanced, and the like. Or, it should be interpreted as a comprehensive meaning of function, and encompasses various coverage areas such as megacell, macrocell, microcell, picocell, femtocell and relay node, RRH, RU, and small cell communication range. to be.

Since the various cells listed above have a base station for controlling each cell, the base station may be interpreted in two senses. i) A device providing a mega cell, a macro cell, a micro cell, a pico cell, a femto cell, a small cell in relation to a radio area, or ii) may indicate the radio area itself. In i) all devices which provide a given wireless area are controlled by the same entity or interact with each other to cooperatively configure the wireless area to direct the base station. The eNB, RRH, antenna, RU, LPN, point, transmit / receive point, transmit point, receive point, and the like, according to the configuration of the radio region, become an embodiment of the base station. In ii), the base station may indicate the radio area itself to receive or transmit a signal from a viewpoint of a user terminal or a neighboring base station.

Therefore, megacells, macrocells, microcells, picocells, femtocells, small cells, RRHs, antennas, RUs, low power nodes (LPNs), points, eNBs, transmit / receive points, transmit points, and receive points are collectively referred to as base stations. do.

In the present specification, the user terminal and the base station are two transmitting and receiving entities used to implement the technology or technical idea described in this specification in a comprehensive sense and are not limited by the terms or words specifically referred to. The user terminal and the base station are two types of uplink or downlink transmitting / receiving subjects used to implement the technology or the technical idea described in the present invention, and are used in a generic sense and are not limited by the terms or words specifically referred to. Here, the uplink (Uplink, UL, or uplink) refers to a method for transmitting and receiving data to the base station by the user terminal, the downlink (Downlink, DL, or downlink) means to transmit and receive data to the user terminal by the base station It means the way.

There is no limitation on the multiple access scheme applied to the wireless communication system. Various multiple access techniques such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), OFDM-FDMA, OFDM-TDMA, OFDM-CDMA Can be used. One embodiment of the present invention can be applied to resource allocation in the fields of asynchronous wireless communication evolving to LTE and LTE-Advanced through GSM, WCDMA, HSPA, and synchronous wireless communication evolving to CDMA, CDMA-2000 and UMB. The present invention should not be construed as being limited or limited to a specific wireless communication field, but should be construed as including all technical fields to which the spirit of the present invention can be applied.

The uplink transmission and the downlink transmission may use a time division duplex (TDD) scheme that is transmitted using different times, or may use a frequency division duplex (FDD) scheme that is transmitted using different frequencies.

In addition, in systems such as LTE and LTE-Advanced, a standard is configured by configuring uplink and downlink based on one carrier or a pair of carriers. The uplink and the downlink include a Physical Downlink Control CHannel (PDCCH), a Physical Control Format Indicator CHannel (PCFICH), a Physical Hybrid ARQ Indicator CHannel (PHICH), a Physical Uplink Control CHannel (PUCCH), an Enhanced Physical Downlink Control CHannel (EPDCCH), and the like. Control information is transmitted through the same control channel, and data is configured by a data channel such as a physical downlink shared channel (PDSCH) and a physical uplink shared channel (PUSCH).

On the other hand, control information may also be transmitted using an enhanced PDCCH (EPDCCH or extended PDCCH).

In the present specification, a cell means a component carrier having a coverage of a signal transmitted from a transmission / reception point or a signal transmitted from a transmission point or a transmission / reception point, and the transmission / reception point itself. Can be.

A wireless communication system to which embodiments are applied may be a coordinated multi-point transmission / reception system (CoMP system) or a coordinated multi-antenna transmission scheme in which two or more transmission / reception points cooperate to transmit a signal. antenna transmission system), a cooperative multi-cell communication system. The CoMP system may include at least two multiple transmission / reception points and terminals.

The multiple transmit / receive point is at least one having a base station or a macro cell (hereinafter referred to as an eNB) and a high transmission power or a low transmission power in a macro cell region, which is wired controlled by an optical cable or an optical fiber to the eNB. May be RRH.

In the following, downlink refers to a communication or communication path from a multiple transmission / reception point to a terminal, and uplink refers to a communication or communication path from a terminal to multiple transmission / reception points. In downlink, a transmitter may be part of multiple transmission / reception points, and a receiver may be part of a terminal. In uplink, a transmitter may be part of a terminal, and a receiver may be part of multiple transmission / reception points.

Hereinafter, a situation in which a signal is transmitted and received through a channel such as a PUCCH, a PUSCH, a PDCCH, an EPDCCH, and a PDSCH may be expressed in the form of 'sending and receiving a PUCCH, a PUSCH, a PDCCH, an EPDCCH, and a PDSCH.'

In addition, hereinafter, a description of transmitting (receiving) or receiving a PDCCH or transmitting or receiving a signal through the PDCCH may be used as a meaning including transmitting or receiving an EPDCCH or transmitting (receiving) or receiving a signal through the EPDCCH.

That is, the physical downlink control channel described below may mean PDCCH or EPDCCH, and may also be used to include both PDCCH and EPDCCH.

In addition, for convenience of description, the EPDCCH, which is an embodiment of the present invention, may be applied to the portion described as the PDCCH, and the EPDCCH may be applied to the portion described as the EPDCCH as an embodiment of the present invention.

Meanwhile, high layer signaling described below includes RRC signaling for transmitting RRC information including an RRC parameter.

The base station or eNB 20 performs downlink transmission to the terminals 10. The eNB includes downlink control information and an uplink data channel (eg, a physical downlink shared channel (PDSCH), which is a primary physical channel for unicast transmission, and scheduling required to receive the PDSCH. For example, a physical downlink control channel (PDCCH) for transmitting scheduling grant information for transmission on a physical uplink shared channel (PUSCH) may be transmitted. Hereinafter, the transmission and reception of signals through each channel will be described in the form of transmission and reception of the corresponding channel.

Referring to FIG. 1, the base station 20 transmits downlink control information (DCI) to the terminal 10 through a PDCCH / EPDCCH. The DCI may include a downlink scheduling assignment including PDSCH resource information or an uplink scheduling grant including PUSCH resource information.

That is, the base station 20 uses DCI to allocate uplink / downlink data transmission resources to the terminal 10 and transmits the same to the terminal 10 using a downlink control channel. The downlink control channel may be classified into a PDCCH and an EPDCCH according to a location of a transmission resource used for transmitting a DCI.

The PDCCH is transmitted in a control region established through a control format indicator (CFI). The control region is formed over the entire downlink bandwidth and consists of 1 to 4 OFDM symbols for each subframe according to the CFI setting value.

The EPDCCH is transmitted using the remaining transmission resources except for the control region in each subframe. The transmission resource used for EPDCCH transmission is allocated to a subframe predefined by upper layer signaling (for example, RRC (Radio Resource Control)) and a plurality of predefined physical resource block (PRB) pairs for each UE. Can only be used.

When transmitting DCI through the PDCCH, a basic transmission resource unit may be referred to as a control channel element (CCE). One CCE may consist of nine Resource Element Groups (REGs), and one REG may consist of four Resource Elements (REs).

When transmitting DCI through EPDCCH, the basic transmission resource unit may be referred to as ECCE (Enhanced CCE). One ECCE is composed of 4 or 8 EREGs (Enhanced REGs) according to cyclic prefix length and / or TDD configuration, and one EREG is variable depending on RE used for RS (Reference Signal) transmission. It may be composed of a plurality of RE.

The base station 20 may set the number of CCEs used to transmit one DCI through the PDCCH according to the channel condition of the terminal. This is called an aggregation level, and 1, 2, 4, or 8 CCEs may be used according to the channel condition of the UE.

In addition, the base station 20 may set the number of ECCEs used when transmitting one DCI through the EPDCCH according to the channel condition of the terminal. This is called an aggregation level, and 1, 2, 4, 8, 16, or 32 ECCEs may be used according to the channel condition of the UE.

As described above, the PDCCH / EPDCCH is composed of a plurality of CCE / ECCE, the base station can transmit a plurality of DCI to a plurality of terminals in every subframe. In this case, the UE does not separately provide CCE / ECCE allocation information (that is, CCE combining level information and CCE transmission resource location information used for one DCI transmission) necessary for the UE to receive DCI through PDCCH / EPDCCH. Therefore, the terminal performs blind decoding on the possible coupling level and the CCE / ECCE transmission resource to confirm the DCI transmitted to the terminal.

Since the UE cannot realistically blind-decode all possible CCE / ECCE combinations for each coupling level for all CCEs / ECCEs present in the PDCCH / EPDCCH, the PDCCH configured with pre-defined CCE / ECCE indices for each UE. Blind decoding is performed only on a candidate / EPDCCH candidate. The CCE index / ECCE index constituting the PDCCH candidate / EPDCCH candidate for each coupling level may be defined as a function of a coupling level, a value of a Radio Network Temporary Identifier (RNTI), and a slot number (or subframe number). The UE may perform blind decoding only on a limited number of PDCCH candidates / EPDCCH candidates at each coupling level in every subframe.

As an example, FIG. 2 illustrates a method of blind decoding a PDCCH / EPDCCH by a general terminal and receiving a PDSCH. Referring to FIG. 2, the UE attempts blind decoding of the PDCCH / EPDCCH with respect to the PDCCH candidate / EPDCCH candidate. A cyclic redundancy check (CRC) is added to the DCI, and the UE checks the CRC to confirm the DCI transmitted to the DCI. When checking the DCI transmitted to itself as a result of the CRC check, the UE acquires downlink scheduling information included in the DCI and decodes the PDSCH using downlink data transmission resources in the same subframe as the subframe in which the DCI is transmitted. do.

2 illustrates blind decoding PDCCH / EPDCCH and obtaining PDSCH scheduling information. In a manner similar to that of FIG. 2, PUSCH scheduling information may also be obtained by blind decoding PDCCH / EPDCCH.

In the conventional 3GPP LTE / LTE-Advanced system, a PDCCH defined in a Rel-10 or lower system and an EPDCCH newly defined in a Release-11 system are used as a downlink control information (DCI) transmission channel for a terminal. .

3 illustrates four PDCCH formats. In the case of the PDCCH, four PDCCH formats as shown in FIG. 3 are transmitted for link adaptation according to downlink radio channel quality and DCI size of the UE. In FIG. 4, the number of CCEs represents an aggregation level.

4 is a diagram showing the number of EREGs by ECCE. In Figure 4

The value of (Number of EREGs per ECCE) is determined according to the characteristics of the subframe, and in the case of the normal cyclic prefix, it is a normal subframe or a special subframe of 3, 4, and 8 settings. Special subframe,

configuration

3, 4, 8) is 4. On the other hand, in the case of an extended cyclic prefix, a normal subframe or a special subframe of 1, 2, 3, 5, and 6 configuration (Special subframe,

configuration

1, 2, 3, 5, 6) ) Is 8.

5 is a diagram for Supported EPDCCH formats. In FIG. 5, it is divided into case A and case B, and is divided into five types according to localized transmission and distributed transmission, respectively.

That is, in the case of EPDCCH, five EPDCCH formats are transmitted according to FIGS. 4 and 5 for link adaptation for DCI transmission.

In the existing LTE / LTE-Advanced system, the PDCCH / EPDCCH including one downlink allocation (DL assignment) DCI for PDSCH resource allocation to any UE is transmitted through one downlink subframe. In addition, regardless of the PDCCH / EPDCCH format, a downlink subframe in which a DL allocation PDCCH or EPDCCH including PDSCH resource allocation information is transmitted and a subframe in which the corresponding PDSCH transmission is performed are the same. That is, PDSCH transmission according to DL allocation information is defined in a downlink subframe in which DL allocation DCI transmission is performed for an arbitrary UE.

[LTE 기반의 저가형 MTC][LTE-based low-cost MTC]

As LTE networks proliferate, mobile operators want to minimize the number of Radio Access Terminals (RATs) to reduce network maintenance costs. However, MTC products based on conventional GSM / GPRS networks are increasing, and MTCs using low data rates can be provided at low cost. Therefore, since the mobile operators use the LTE network for general data transmission and the GSM / GPRS network for the MTC, there is a problem of operating two RATs, which are inefficient use of the frequency band. It becomes burden on profit.

In order to solve this problem, the cheap MTC terminal using the GSM / EGPRS network should be replaced with the MTC terminal using the LTE network, for this purpose, various requirements for reducing the price of the LTE MTC terminal is proposed.

In order to support the low-cost LTE MTC terminal, there may be mentioned, for example, technologies such as narrowband support / single RF chain / half duplex FDD / long discontinued reception (DRX). However, the above methods, which are considered to lower the price, may reduce the performance of the MTC terminal compared to the conventional LTE terminal.

In addition, since about 20% of MTC terminals supporting MTC services such as smart metering are installed in a 'deep indoor' environment such as a basement, for successful MTC data transmission, the coverage of LTE MTC terminals is conventional LTE. It should be improved by about 20dB compared to the coverage of the terminal. In addition, if the performance reduction due to the specification change is further considered, the coverage of the LTE MTC terminal should be improved by 20 dB or more.

As described above, various methods for robust transmission such as PSD boosting or low coding rate and time domain repetition are used to improve coverage while lowering the LTE MTC terminal price. This is considered for each physical channel.

The requirements of the LTE-based low-cost MTC terminal is as follows.

1) The data transmission rate must satisfy the data transmission rate provided by the minimum EGPRS-based MTC terminal, that is, downlink 118.4kbps, uplink 59.2kbps.

2) Frequency efficiency should be improved significantly compared to GSM / EGPRS MTC terminal.

3) The service area provided shall not be smaller than that provided by the GSM / EGPRS MTC terminal.

4) Power consumption should not be greater than GSM / EGPRS MTC terminal.

5) Legacy LTE terminal and LTE MTC terminal should be available in the same frequency.

6) Reuse existing LTE / SAE networks.

7) Optimization is performed not only in the FDD mode but also in the TDD mode.

8) Low cost LTE MTC terminal should support limited mobility and low power consumption module.

In order to support 20dB enhanced coverage compared to the general LTE terminal, the MTC terminal repetitively transmits a PDCCH or EPDCCH transmission made in one downlink subframe unit through a plurality of downlink subframes, The MTC terminal also needs to perform decoding by combining PDCCHs or EPDCCHs received through a plurality of downlink subframes. In this case, when the DL allocation DCI is transmitted through the corresponding PDCCH or EPDCCH, the DL allocation DCI based on the same downlink subframe in the existing LTE / LTE-Advanced terminal and the PDSCH transmission / reception timing relationship accordingly, for the MTC terminal There is a need for a new definition of the repeated PDCCH and EPDCCH transmission and reception and PDSCH transmission and reception timing relationship.

The present invention proposes a transmission format of a PDCCH or an EPDCCH for an MTC terminal and a PDSCH transmission scheme according thereto.

In particular, we define a new PDCCH / EPDCCH format for downlink control information (DCI) transmission for MTC UE, and propose a PDSCH transmission method based on the same.

The present invention proposes a PDCCH / EPDCCH transmission method for DL allocation DCI transmission including PDSCH scheduling information in a base station for an MTC terminal, a PDSCH transmission method based thereon, and a PDCCH / EPDCCH and PDSCH reception method of an MTC terminal based thereon. .

In particular, the relationship between the PDCCH / EPDCCH transmission downlink subframe including the DL allocation and the PDSCH transmission downlink subframe is defined. In particular, a method of defining a PDSCH transmission subframe and a PDSCH repetition number for an MTC terminal is proposed.

As described above, in the conventional LTE / LTE-Advanced system, the PDCCH or EPDCCH including one DCI for any UE is transmitted through one downlink subframe. For example, PDCCH / EPDCCH including DL allocation DCI which is PDSCH resource allocation information for any LTE / LTE-Advanced UE, or PDCCH / EPDCCH including UL grant DCI which is PUSCH resource allocation information. One PDCCH or EPDCCH including one DCI for one UE or UE group is transmitted in one downlink subframe. In particular, in case of DL allocation PDCCH or EPDCCH for transmitting PDSCH resource allocation information, the PDSCH transmission is performed in the same subframe as the downlink subframe in which the corresponding DL allocation PDCCH or EPDCCH transmission is performed. However, as described above, in case of an MTC terminal, a PDCCH or an EPDCCH including one DCI may be repeatedly transmitted through a plurality of downlink subframes to support enhanced coverage. In this case, when the PDCCH / EPDCCH for transmitting the DL allocation DCI for any MTC terminal is transmitted through any N downlink subframes, the downlink subframe in which the corresponding PDCCH / EPDCCH transmission is performed and the PDSCH transmission accordingly It is necessary to define the relationship with the downlink subframe.

Hereinafter, a PDCCH / EPDCCH transmission method for DL allocation DCI transmission including PDSCH scheduling information in a base station for an MTC terminal, the relationship between a PDCCH / EPDCCH transmission downlink subframe including DL allocation and a PDSCH transmission downlink subframe A downlink data channel transmission / reception method for a specified MTC terminal and an apparatus therefor will be described.

방법 1. PDSCH 출발 서브프레임(PDSCH starting subframe) Method 1. PDSCH starting subframe

If the timing relationship between the PDCCH / EPDCCH and the PDSCH of the existing LTE / LTE-Advanced system is maintained, the MTC UE transmits all N downlink subframes in which the corresponding PDCCH / EPDCCH transmission is performed until decoding of the PDCCH / EPDCCH is completed. Buffering must be performed for the PDSCH region of the band. This may be inefficient in terms of complexity of the MTC terminal. In order to solve this problem, in the present invention, when the downlink subframe in which the last PDCCH / EPDCCH repetition is performed is called DL subframe #M, the PDSCH transmission start downlink subframe is defined as DL subframe # (M + k). do. However, k value can be limited to an integer of 0 or more.

6 is a diagram for transmitting a PDSCH after repeated transmission of a PDCCH / EPDCCH according to an embodiment of the present invention. The case of repetitive transmission of the PDCCH / EPDCCH and timing (k = 1) of the PDSCH thereto is shown. We can set k as 1 above. That is, PDSCH transmission may be defined from the next subframe of the last transmission subframe of the repeated PDCCH or EPDCCH. That is, as shown in FIG. 6, from DL subframe # (M-N + 1) indicated by 611 to PDCCH or EPDCCH including one DL-allocated DCI for an arbitrary MTC UE, to DL subframe #M indicated by 619. When repeated transmission through N DL subframes, PDSCH transmission corresponding to the DL allocation information is performed from DL subframe # (M + 1) indicated by 621 through DL subframe # (M + P) indicated by 629. It can be done until. However, P is the number of repeated PDSCH transmissions for the corresponding MTC terminal.

In other words, PDCCH / EPDCCH transmission (PDCCH / EPDCCH transmission) repeated in FIG. 6 corresponds to 631, 632, ..., 639, and these are repeated N times (Number of repetition = N). The subframe number of the subframe 619 in which transmission has been completed is #M, and then PDSCH is transmitted through P (Number of repetition = P) from # (M + 1) subframe 621 (corresponding PDSCH). transmission). PDSCH repeated P times are 641, 642, ..., 649, respectively. "1" of M + 1 shows the case where the timing k of the PDSCH is 1. As another embodiment for defining the corresponding k value, k = 4 may be fixed according to a timing relationship between a PDCCH / EPDCCH transmission including a UL grant and a PUSCH transmission. That is, the PDSCH transmission may be defined to start from 4 subframes after the last transmission subframe of the repeated PDCCH / EPDCCH.

In addition to the above specific examples of k values, any integer satisfying k ≧ 0 may be included in the scope of the present invention.

방법 2. PDSCH 반복 횟수(Number of PDSCH repetition)Method 2.Number of PDSCH repetition

When the MTC UE transmits PDSCH according to DL allocation DCI, the number of PDSCH repetitions to be applied, P value, is a function of N value which is the number of repetitions of DL allocation PDCCH / EPDCCH containing corresponding PDSCH allocation information, or as a function of PDCCH / EPDCCH format including the same. Can be determined. As an example of this, the corresponding P value may be set in proportion to the N value. That is, it can be defined that the relation of P = a • N holds. Where a is any positive constant.

For example, it can be defined as a = 1/2. In this case, the corresponding PDSCH repetition number and P may be defined as half the repetition number and N values of the PDCCH / EPDCCH for transmitting the corresponding PDSCH allocation information.

As another method of determining the corresponding P value, any arbitrary plurality of PDSCH formats including the corresponding P value may be defined and included in the DL allocation DCI for transmission. The PDSCH format may include or part of PRB allocation information, MCS value, etc. in addition to the PDSCH repetition number P value as shown in FIG. 6. However, the number of specific PDSCH formats, the number of PRB allocations per PDSCH format, and the number of repetitions may be variously defined, and there is no limitation on this value.

FIG. 7 is a relationship in which the number of PRBs, the number of repetitions, and the Modulation and Coding Scheme (MCS) are set according to a PDSCH format according to an embodiment of the present invention. Each of the values a, b, c, d, e, f, g, and h may be determined according to an embodiment. The MCS may be defined later according to the format of the PDSCH.

As another method of determining the number of PDSCH repetitions, a coverage level may be defined according to radio channel quality for each MTC terminal, and a PDSCH repetition number P value may be defined for each corresponding coverage level. In this case, the coverage level for any terminal may be set by the base station or implicitly set for each terminal through a PRACH procedure of the corresponding MTC terminal.

In FIG. 8, the number N of repetitive transmissions is 5 and shows a process of performing repetitive transmissions of two PDSCHs (P = 2) after one subframe (k = 1) after repeated transmissions.

The base station 801 generates a downlink signal including the PDCCH or EPDCCH for the terminal 809 (S810). In operation S815, the generated downlink signal is transmitted in a first downlink subframe. This is the first transmission of repetitive transmission, the terminal 809 receives the PDCCH or EPDCCH of the downlink signal (S819). The base station repeatedly repeats a process of generating and transmitting a downlink signal including a PDCCH or an EPDCCH for the terminal 809. The base station generates a downlink signal including a PDCCH or EPDCCH for the terminal 809 for five transmissions which are the last repetitive transmission (S820). In operation S825, the generated downlink signal is transmitted in a fifth downlink subframe. This is the fifth transmission of repetitive transmission, and the terminal 809 receives the PDCCH or EPDCCH of the downlink signal (S829). When the repetitive transmission is completed, the base station 801 performs two times in the next subframe (since k = 1) of the fifth subframe in which the repetitive transmission is completed according to the PDSCH scheduling information included in the PDCCH or EPDCCH repeatedly transmitted in S815 through S825. PDSCH repeats transmission. The base station 801 generates a downlink signal including a PDSCH for the terminal (S830) and transmits it to the terminal 809 as a downlink signal in a sixth downlink subframe (S835). This is the first transmission of the PDSCH repetitive transmission. The terminal receives the PDSCH of the downlink signal (S839). The base station 801 generates a downlink signal including a PDSCH for the terminal (S840) and transmits it to the terminal 809 as a downlink signal in a seventh downlink subframe (S845). This is the second transmission of the PDSCH repetitive transmission. The terminal receives the PDSCH of the downlink signal (S849).

9 is a diagram illustrating a process in which a base station repeatedly transmits a PDCCH or an EPDCCH to a UE according to an embodiment of the present invention. The base station transmits the PDCCH or EPDCCH including the PDSCH scheduling information for the terminal based on the process of FIG. 9 and the PDSCH accordingly.

The base station repeatedly transmits the PDCCH or the EPDCCH through N downlink subframes (S910). The PDSCH is repeatedly transmitted through P downlink subframes according to the scheduling information included in the repeatedly transmitted PDCCH or EPDCCH (S920). Here, when the downlink subframe index at which repetitive transmission of the PDCCH or the EPDCCH is terminated is M, the downlink subframe index at which the PDSCH repeating transmission is started is M + k. That is, the PDSCH is transmitted in the subframe after k in the subframe in which repeated transmission of the PDCCH / EPDCCH is completed. The value of k may have an integer value of 0 or greater, and in one embodiment, the k value may be 1. Meanwhile, the terminal to receive the repeated transmission may be a terminal supporting MTC, and the value P of the repeated transmission of the PDSCH to be repeatedly transmitted may have an integer value of 1 or more. In another embodiment, as described in Method 2, a P value for PDSCH repetitive transmission may be determined using a format of PDCCH or EPDCCH and one or more of N as shown in FIG. 7. That is, the format and the value of N may be given as arguments of the function, and the base station and the terminal may share information in the form as shown in FIG. 7.

10 is a diagram illustrating a process of repeatedly receiving a PDCCH or EPDCCH from a base station by a terminal according to an embodiment of the present invention. The terminal receives a PDCCH or EPDCCH including PDSCH scheduling information from the base station and the PDSCH accordingly based on the process of FIG. 10.

The UE repeatedly receives the PDCCH or the EPDCCH through N downlink subframes (S1010). The PDSCH is repeatedly received through P downlink subframes according to the scheduling information included in the repeatedly received PDCCH or EPDCCH (S1020). Here, when the downlink subframe index at which repeated reception of the PDCCH or the EPDCCH is terminated is M, the downlink subframe index at which the PDSCH repeat reception is started is M + k. That is, the PDSCH is received in the subframe after k in the subframe in which repeated reception of the PDCCH / EPDCCH is completed. The value of k may have an integer value of 0 or greater, and in one embodiment, the k value may be 1. Meanwhile, the terminal may be a terminal supporting MTC, and the value of P, which is a value for repetitive transmission of the PDSCH to be repeatedly received, may have an integer value of 1 or more. In another embodiment, as described in Method 2, a P value for PDSCH repetitive reception may be determined using a format of PDCCH or EPDCCH and one or more of N as shown in FIG. 7. That is, the format and the value of N may be given as arguments of the function, and the base station and the terminal may share information in the form as shown in FIG. 7.

Referring to FIG. 11, the base station 1100 according to another embodiment includes a controller 1110, a transmitter 1120, and a receiver 1130.

The control unit 1110 is a PDCCH / EPDCCH transmission method for DL allocation DCI transmission including PDSCH scheduling information in a base station for an MTC terminal required to perform the above-described invention. Controls the overall operation of the base station according to performing a downlink data channel transmission / reception method for an MTC terminal in which a relationship between a subframe and a corresponding PDSCH transmission downlink subframe is specified.

The transmitter 1120 and the receiver 1130 are used to transmit and receive signals, messages, and data necessary for carrying out the above-described present invention.

In more detail, the base station of FIG. 11 transmits a PDCCH or EPDCCH including PDSCH scheduling information for a UE and the PDSCH accordingly, and repeatedly transmits the PDCCH or EPDCCH. That is, the transmitter 1120 repeatedly transmits the PDCCH or the EPDCCH through N downlink subframes and repeatedly transmits the PDSCH through P downlink subframes, and the controller 1110 controls the PDCCH or the EPDCCH. If the downlink subframe index at which repeating transmission is terminated is M, the transmitter 1120 controls the downlink subframe index at which the PDSCH repeating transmission is started to be M + k. K denotes a PDSCH transmission interval after repeated PDCCH / EPDCCH transmission, and the controller 1110 may control the transmitter 1120 such that the value of k has an integer value equal to or greater than zero. In an embodiment, the controller 1110 may control the transmitter 1120 such that the value of k becomes 1. In addition, the terminal may be a terminal that supports MTC. The controller 1110 may control the transmitter 1120 such that the value of P, which is the number of repeated PDSCH transmissions, has an integer value of 1 or more. Similarly to the method of functionalizing information on the PDSCH repetitive transmission in Method 2, the controller 1110 may determine the P using any one or more of the format of the PDCCH or EPDCCH and the N.

Referring to FIG. 12, the user terminal 1200 according to another embodiment includes a receiver 1230, a controller 1210, and a transmitter 1220.

The receiver 1230 receives downlink control information, data, and a message from a base station through a corresponding channel.

Also, the control unit 1210 is a PDCCH / EPDCCH transmission method for DL allocation DCI transmission including PDSCH scheduling information in a base station for an MTC terminal required to perform the above-described invention, and transmits PDCCH / EPDCCH transmission downlink including DL allocation. Controls the overall operation of the UE according to performing a downlink data channel transmission / reception method for an MTC UE having a relationship between a link subframe and a PDSCH transmission downlink subframe.

The transmitter 1220 transmits uplink control information, data, and a message to a base station through a corresponding channel.

In more detail, the terminal of FIG. 12 receives a PDCCH or EPDCCH including PDSCH scheduling information from the base station and the PDSCH accordingly, and repeatedly receives the PDCCH or EPDCCH.

The receiver 1230 repeatedly receives the PDCCH or the EPDCCH through N downlink subframes, and repeatedly receives the PDSCH through P downlink subframes. When the downlink subframe index at which repetitive reception of the PDCCH or the EPDCCH is terminated is M, the control unit 1210 receives the downlink subframe index at which the PDSCH repeat reception is started to be M + k. To control. That is, the receiver 1230 repeatedly receives the PDCCH or the EPDCCH through N downlink subframes and repeatedly receives the PDSCH through P downlink subframes, and the controller 1210 controls the PDCCH or the EPDCCH. When the downlink subframe index at which repeated reception is terminated is M, the downlink subframe index at which the PDSCH repeat reception is started is controlled by the receiver 1230 such that M + k. K denotes a PDSCH transmission interval after repeated PDCCH / EPDCCH transmission, and the controller 1210 may control the receiver 1230 such that the value of k has an integer value equal to or greater than zero. In an embodiment, the controller 1210 may control the receiver 1230 such that the value of k becomes 1. In addition, the terminal 1200 may be a terminal supporting the MTC. The controller 1210 may control the receiver 1230 such that the value of P, which is the number of repeated PDSCH transmissions, has an integer value of 1 or more. Similarly to the method of functionalizing information on the PDSCH repetitive transmission in Method 2, the controller 1210 may determine the P using any one or more of the format of the PDCCH or EPDCCH and the N.

PDCCH / EPDCCH transmission method for DL allocation DCI transmission including PDSCH scheduling information in a base station for an MTC terminal so far, the PDCCH / EPDCCH transmission downlink subframe including DL allocation and the PDSCH transmission downlink subframe A method and apparatus for downlink data channel transmission and reception for a MTC terminal having a specified relationship have been described.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

CROSS-REFERENCE TO RELATED APPLICATIONCROSS-REFERENCE TO RELATED APPLICATION

This patent application is related to the patent application No. 10-2013-0116812 filed in Korea on September 30, 2013 and the patent application No. 10-2014-0021106 filed in Korea on February 24, 2014. Priority is claimed under section (a) (35 USC § 119 (a)), all of which is incorporated by reference in this patent application. In addition, if this patent application claims priority for the same reason for countries other than the United States, all its contents are incorporated into this patent application by reference.

Claims

In a method for a base station to transmit a physical downlink control channel (PDCCH) or enhanced physical downlink control channel (EPDCCH) including PDSCH (Physical Downlink Shared CHannel) scheduling information for the terminal and the PDSCH accordingly;

Repeatedly transmitting the PDCCH or the EPDCCH through N downlink subframes; And

Repeatedly transmitting the PDSCH through P downlink subframes,

And if the downlink subframe index at which repetitive transmission of the PDCCH or the EPDCCH is terminated is M, the downlink subframe index at which the PDSCH repeating transmission is started is M + k.
The method of claim 1,

The value of k has an integer value of 0 or more.
The method of claim 1,

The value of k is 1, characterized in that.
The method of claim 1,

The terminal is characterized in that the MTC (Machine Type Communications) terminal.
The method of claim 1,

Wherein the value of P has an integer value of at least one.
The method of claim 1,

The P is determined using any one or more of the format of the PDCCH or EPDCCH and the N.
In a method for a terminal to receive a physical downlink control channel (PDCCH) or enhanced physical downlink control channel (EPDCCH) including PDSCH (Physical Downlink Shared CHannel) scheduling information from the base station and accordingly

Repeatedly receiving the PDCCH or the EPDCCH through N downlink subframes; And

Repeatedly receiving the PDSCH through P downlink subframes,

If the downlink subframe index at which repeated reception of the PDCCH or the EPDCCH is terminated is M, the downlink subframe index at which the PDSCH repeat reception is started is M + k.
The method of claim 7, wherein

The value of k has an integer value of 0 or more.
The method of claim 7, wherein

The value of k is 1, characterized in that.
The method of claim 7, wherein

The terminal is characterized in that the MTC (Machine Type Communications) terminal.
The method of claim 7, wherein

Wherein the value of P has an integer value of at least one.
The method of claim 7, wherein

The P is determined using any one or more of the format of the PDCCH or EPDCCH and the N.
In the base station for transmitting a Physical Downlink Control CHannel (PDCCH) or Enhanced Physical Downlink Control CHannel (EPDCCH) including PDSCH scheduling information for a UE and the PDSCH accordingly,

A transmitter for repeatedly transmitting the PDCCH or the EPDCCH through N downlink subframes and repeatedly transmitting the PDSCH through P downlink subframes; And

And a control unit for controlling the transmitter such that the downlink subframe index at which the PDSCH repeat transmission is started is M + k when the downlink subframe index at which repeated transmission of the PDCCH or the EPDCCH is terminated is M + k.
The method of claim 13,

And the control unit controls the transmitter so that the value of k has an integer value greater than or equal to zero.
The method of claim 13,

The control unit controls the transmitter so that the value of k is 1.
The method of claim 13,

The terminal is a base station, characterized in that the MTC (Machine Type Communications) terminal.
The method of claim 13,

The control unit controls the transmitter so that the value of P has an integer value of 1 or more.
The method of claim 13,

The controller determines the P using any one or more of the format of the PDCCH or EPDCCH and the N.